net/batman-adv/main.c

   1 /* Copyright (C) 2007-2013 B.A.T.M.A.N. contributors:
   2  *
   3  * Marek Lindner, Simon Wunderlich
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of version 2 of the GNU General Public
   7  * License as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  17  * 02110-1301, USA
  18  */
  19
  20 #include <linux/crc32c.h>
  21 #include <linux/highmem.h>
  22 #include "main.h"
  23 #include "sysfs.h"
  24 #include "debugfs.h"
  25 #include "routing.h"
  26 #include "send.h"
  27 #include "originator.h"
  28 #include "soft-interface.h"
  29 #include "icmp_socket.h"
  30 #include "translation-table.h"
  31 #include "hard-interface.h"
  32 #include "gateway_client.h"
  33 #include "bridge_loop_avoidance.h"
  34 #include "distributed-arp-table.h"
  35 #include "vis.h"
  36 #include "hash.h"
  37 #include "bat_algo.h"
  38
  39
  40 /* List manipulations on hardif_list have to be rtnl_lock()'ed,
  41  * list traversals just rcu-locked
  42  */
  43 struct list_head batadv_hardif_list;
  44 static int (*batadv_rx_handler[256])(struct sk_buff *,
  45                                      struct batadv_hard_iface *);
  46 char batadv_routing_algo[20] = "BATMAN_IV";
  47 static struct hlist_head batadv_algo_list;
  48
  49 unsigned char batadv_broadcast_addr[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
  50
  51 struct workqueue_struct *batadv_event_workqueue;
  52
  53 static void batadv_recv_handler_init(void);
  54
  55 static int __init batadv_init(void)
  56 {
  57         INIT_LIST_HEAD(&batadv_hardif_list);
  58         INIT_HLIST_HEAD(&batadv_algo_list);
  59
  60         batadv_recv_handler_init();
  61
  62         batadv_iv_init();
  63
  64         batadv_event_workqueue = create_singlethread_workqueue("bat_events");
  65
  66         if (!batadv_event_workqueue)
  67                 return -ENOMEM;
  68
  69         batadv_socket_init();
  70         batadv_debugfs_init();
  71
  72         register_netdevice_notifier(&batadv_hard_if_notifier);
  73
  74         pr_info("B.A.T.M.A.N. advanced %s (compatibility version %i) loaded\n",
  75                 BATADV_SOURCE_VERSION, BATADV_COMPAT_VERSION);
  76
  77         return 0;
  78 }
  79
  80 static void __exit batadv_exit(void)
  81 {
  82         batadv_debugfs_destroy();
  83         unregister_netdevice_notifier(&batadv_hard_if_notifier);
  84         batadv_hardif_remove_interfaces();
  85
  86         flush_workqueue(batadv_event_workqueue);
  87         destroy_workqueue(batadv_event_workqueue);
  88         batadv_event_workqueue = NULL;
  89
  90         rcu_barrier();
  91 }
  92
  93 int batadv_mesh_init(struct net_device *soft_iface)
  94 {
  95         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
  96         int ret;
  97
  98         spin_lock_init(&bat_priv->forw_bat_list_lock);
  99         spin_lock_init(&bat_priv->forw_bcast_list_lock);
 100         spin_lock_init(&bat_priv->tt.changes_list_lock);
 101         spin_lock_init(&bat_priv->tt.req_list_lock);
 102         spin_lock_init(&bat_priv->tt.roam_list_lock);
 103         spin_lock_init(&bat_priv->tt.last_changeset_lock);
 104         spin_lock_init(&bat_priv->gw.list_lock);
 105         spin_lock_init(&bat_priv->vis.hash_lock);
 106         spin_lock_init(&bat_priv->vis.list_lock);
 107
 108         INIT_HLIST_HEAD(&bat_priv->forw_bat_list);
 109         INIT_HLIST_HEAD(&bat_priv->forw_bcast_list);
 110         INIT_HLIST_HEAD(&bat_priv->gw.list);
 111         INIT_LIST_HEAD(&bat_priv->tt.changes_list);
 112         INIT_LIST_HEAD(&bat_priv->tt.req_list);
 113         INIT_LIST_HEAD(&bat_priv->tt.roam_list);
 114
 115         ret = batadv_originator_init(bat_priv);
 116         if (ret < 0)
 117                 goto err;
 118
 119         ret = batadv_tt_init(bat_priv);
 120         if (ret < 0)
 121                 goto err;
 122
 123         batadv_tt_local_add(soft_iface, soft_iface->dev_addr,
 124                             BATADV_NULL_IFINDEX);
 125
 126         ret = batadv_vis_init(bat_priv);
 127         if (ret < 0)
 128                 goto err;
 129
 130         ret = batadv_bla_init(bat_priv);
 131         if (ret < 0)
 132                 goto err;
 133
 134         ret = batadv_dat_init(bat_priv);
 135         if (ret < 0)
 136                 goto err;
 137
 138         atomic_set(&bat_priv->gw.reselect, 0);
 139         atomic_set(&bat_priv->mesh_state, BATADV_MESH_ACTIVE);
 140
 141         return 0;
 142
 143 err:
 144         batadv_mesh_free(soft_iface);
 145         return ret;
 146 }
 147
 148 void batadv_mesh_free(struct net_device *soft_iface)
 149 {
 150         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 151
 152         atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
 153
 154         batadv_purge_outstanding_packets(bat_priv, NULL);
 155
 156         batadv_vis_quit(bat_priv);
 157
 158         batadv_gw_node_purge(bat_priv);
 159         batadv_originator_free(bat_priv);
 160
 161         batadv_tt_free(bat_priv);
 162
 163         batadv_bla_free(bat_priv);
 164
 165         batadv_dat_free(bat_priv);
 166
 167         free_percpu(bat_priv->bat_counters);
 168
 169         atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
 170 }
 171
 172 int batadv_is_my_mac(const uint8_t *addr)
 173 {
 174         const struct batadv_hard_iface *hard_iface;
 175
 176         rcu_read_lock();
 177         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 178                 if (hard_iface->if_status != BATADV_IF_ACTIVE)
 179                         continue;
 180
 181                 if (batadv_compare_eth(hard_iface->net_dev->dev_addr, addr)) {
 182                         rcu_read_unlock();
 183                         return 1;
 184                 }
 185         }
 186         rcu_read_unlock();
 187         return 0;
 188 }
 189
 190 /**
 191  * batadv_seq_print_text_primary_if_get - called from debugfs table printing
 192  *  function that requires the primary interface
 193  * @seq: debugfs table seq_file struct
 194  *
 195  * Returns primary interface if found or NULL otherwise.
 196  */
 197 struct batadv_hard_iface *
 198 batadv_seq_print_text_primary_if_get(struct seq_file *seq)
 199 {
 200         struct net_device *net_dev = (struct net_device *)seq->private;
 201         struct batadv_priv *bat_priv = netdev_priv(net_dev);
 202         struct batadv_hard_iface *primary_if;
 203
 204         primary_if = batadv_primary_if_get_selected(bat_priv);
 205
 206         if (!primary_if) {
 207                 seq_printf(seq,
 208                            "BATMAN mesh %s disabled - please specify interfaces to enable it\n",
 209                            net_dev->name);
 210                 goto out;
 211         }
 212
 213         if (primary_if->if_status == BATADV_IF_ACTIVE)
 214                 goto out;
 215
 216         seq_printf(seq,
 217                    "BATMAN mesh %s disabled - primary interface not active\n",
 218                    net_dev->name);
 219         batadv_hardif_free_ref(primary_if);
 220         primary_if = NULL;
 221
 222 out:
 223         return primary_if;
 224 }
 225
 226 static int batadv_recv_unhandled_packet(struct sk_buff *skb,
 227                                         struct batadv_hard_iface *recv_if)
 228 {
 229         return NET_RX_DROP;
 230 }
 231
 232 /* incoming packets with the batman ethertype received on any active hard
 233  * interface
 234  */
 235 int batadv_batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
 236                            struct packet_type *ptype,
 237                            struct net_device *orig_dev)
 238 {
 239         struct batadv_priv *bat_priv;
 240         struct batadv_ogm_packet *batadv_ogm_packet;
 241         struct batadv_hard_iface *hard_iface;
 242         uint8_t idx;
 243         int ret;
 244
 245         hard_iface = container_of(ptype, struct batadv_hard_iface,
 246                                   batman_adv_ptype);
 247         skb = skb_share_check(skb, GFP_ATOMIC);
 248
 249         /* skb was released by skb_share_check() */
 250         if (!skb)
 251                 goto err_out;
 252
 253         /* packet should hold at least type and version */
 254         if (unlikely(!pskb_may_pull(skb, 2)))
 255                 goto err_free;
 256
 257         /* expect a valid ethernet header here. */
 258         if (unlikely(skb->mac_len != ETH_HLEN || !skb_mac_header(skb)))
 259                 goto err_free;
 260
 261         if (!hard_iface->soft_iface)
 262                 goto err_free;
 263
 264         bat_priv = netdev_priv(hard_iface->soft_iface);
 265
 266         if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
 267                 goto err_free;
 268
 269         /* discard frames on not active interfaces */
 270         if (hard_iface->if_status != BATADV_IF_ACTIVE)
 271                 goto err_free;
 272
 273         batadv_ogm_packet = (struct batadv_ogm_packet *)skb->data;
 274
 275         if (batadv_ogm_packet->header.version != BATADV_COMPAT_VERSION) {
 276                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 277                            "Drop packet: incompatible batman version (%i)\n",
 278                            batadv_ogm_packet->header.version);
 279                 goto err_free;
 280         }
 281
 282         /* all receive handlers return whether they received or reused
 283          * the supplied skb. if not, we have to free the skb.
 284          */
 285         idx = batadv_ogm_packet->header.packet_type;
 286         ret = (*batadv_rx_handler[idx])(skb, hard_iface);
 287
 288         if (ret == NET_RX_DROP)
 289                 kfree_skb(skb);
 290
 291         /* return NET_RX_SUCCESS in any case as we
 292          * most probably dropped the packet for
 293          * routing-logical reasons.
 294          */
 295         return NET_RX_SUCCESS;
 296
 297 err_free:
 298         kfree_skb(skb);
 299 err_out:
 300         return NET_RX_DROP;
 301 }
 302
 303 static void batadv_recv_handler_init(void)
 304 {
 305         int i;
 306
 307         for (i = 0; i < ARRAY_SIZE(batadv_rx_handler); i++)
 308                 batadv_rx_handler[i] = batadv_recv_unhandled_packet;
 309
 310         /* batman icmp packet */
 311         batadv_rx_handler[BATADV_ICMP] = batadv_recv_icmp_packet;
 312         /* unicast with 4 addresses packet */
 313         batadv_rx_handler[BATADV_UNICAST_4ADDR] = batadv_recv_unicast_packet;
 314         /* unicast packet */
 315         batadv_rx_handler[BATADV_UNICAST] = batadv_recv_unicast_packet;
 316         /* fragmented unicast packet */
 317         batadv_rx_handler[BATADV_UNICAST_FRAG] = batadv_recv_ucast_frag_packet;
 318         /* broadcast packet */
 319         batadv_rx_handler[BATADV_BCAST] = batadv_recv_bcast_packet;
 320         /* vis packet */
 321         batadv_rx_handler[BATADV_VIS] = batadv_recv_vis_packet;
 322         /* Translation table query (request or response) */
 323         batadv_rx_handler[BATADV_TT_QUERY] = batadv_recv_tt_query;
 324         /* Roaming advertisement */
 325         batadv_rx_handler[BATADV_ROAM_ADV] = batadv_recv_roam_adv;
 326 }
 327
 328 int
 329 batadv_recv_handler_register(uint8_t packet_type,
 330                              int (*recv_handler)(struct sk_buff *,
 331                                                  struct batadv_hard_iface *))
 332 {
 333         if (batadv_rx_handler[packet_type] != &batadv_recv_unhandled_packet)
 334                 return -EBUSY;
 335
 336         batadv_rx_handler[packet_type] = recv_handler;
 337         return 0;
 338 }
 339
 340 void batadv_recv_handler_unregister(uint8_t packet_type)
 341 {
 342         batadv_rx_handler[packet_type] = batadv_recv_unhandled_packet;
 343 }
 344
 345 static struct batadv_algo_ops *batadv_algo_get(char *name)
 346 {
 347         struct batadv_algo_ops *bat_algo_ops = NULL, *bat_algo_ops_tmp;
 348
 349         hlist_for_each_entry(bat_algo_ops_tmp, &batadv_algo_list, list) {
 350                 if (strcmp(bat_algo_ops_tmp->name, name) != 0)
 351                         continue;
 352
 353                 bat_algo_ops = bat_algo_ops_tmp;
 354                 break;
 355         }
 356
 357         return bat_algo_ops;
 358 }
 359
 360 int batadv_algo_register(struct batadv_algo_ops *bat_algo_ops)
 361 {
 362         struct batadv_algo_ops *bat_algo_ops_tmp;
 363         int ret;
 364
 365         bat_algo_ops_tmp = batadv_algo_get(bat_algo_ops->name);
 366         if (bat_algo_ops_tmp) {
 367                 pr_info("Trying to register already registered routing algorithm: %s\n",
 368                         bat_algo_ops->name);
 369                 ret = -EEXIST;
 370                 goto out;
 371         }
 372
 373         /* all algorithms must implement all ops (for now) */
 374         if (!bat_algo_ops->bat_iface_enable ||
 375             !bat_algo_ops->bat_iface_disable ||
 376             !bat_algo_ops->bat_iface_update_mac ||
 377             !bat_algo_ops->bat_primary_iface_set ||
 378             !bat_algo_ops->bat_ogm_schedule ||
 379             !bat_algo_ops->bat_ogm_emit) {
 380                 pr_info("Routing algo '%s' does not implement required ops\n",
 381                         bat_algo_ops->name);
 382                 ret = -EINVAL;
 383                 goto out;
 384         }
 385
 386         INIT_HLIST_NODE(&bat_algo_ops->list);
 387         hlist_add_head(&bat_algo_ops->list, &batadv_algo_list);
 388         ret = 0;
 389
 390 out:
 391         return ret;
 392 }
 393
 394 int batadv_algo_select(struct batadv_priv *bat_priv, char *name)
 395 {
 396         struct batadv_algo_ops *bat_algo_ops;
 397         int ret = -EINVAL;
 398
 399         bat_algo_ops = batadv_algo_get(name);
 400         if (!bat_algo_ops)
 401                 goto out;
 402
 403         bat_priv->bat_algo_ops = bat_algo_ops;
 404         ret = 0;
 405
 406 out:
 407         return ret;
 408 }
 409
 410 int batadv_algo_seq_print_text(struct seq_file *seq, void *offset)
 411 {
 412         struct batadv_algo_ops *bat_algo_ops;
 413
 414         seq_printf(seq, "Available routing algorithms:\n");
 415
 416         hlist_for_each_entry(bat_algo_ops, &batadv_algo_list, list) {
 417                 seq_printf(seq, "%s\n", bat_algo_ops->name);
 418         }
 419
 420         return 0;
 421 }
 422
 423 /**
 424  * batadv_skb_crc32 - calculate CRC32 of the whole packet and skip bytes in
 425  *  the header
 426  * @skb: skb pointing to fragmented socket buffers
 427  * @payload_ptr: Pointer to position inside the head buffer of the skb
 428  *  marking the start of the data to be CRC'ed
 429  *
 430  * payload_ptr must always point to an address in the skb head buffer and not to
 431  * a fragment.
 432  */
 433 __be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr)
 434 {
 435         u32 crc = 0;
 436         unsigned int from;
 437         unsigned int to = skb->len;
 438         struct skb_seq_state st;
 439         const u8 *data;
 440         unsigned int len;
 441         unsigned int consumed = 0;
 442
 443         from = (unsigned int)(payload_ptr - skb->data);
 444
 445         skb_prepare_seq_read(skb, from, to, &st);
 446         while ((len = skb_seq_read(consumed, &data, &st)) != 0) {
 447                 crc = crc32c(crc, data, len);
 448                 consumed += len;
 449         }
 450         skb_abort_seq_read(&st);
 451
 452         return htonl(crc);
 453 }
 454
 455 static int batadv_param_set_ra(const char *val, const struct kernel_param *kp)
 456 {
 457         struct batadv_algo_ops *bat_algo_ops;
 458         char *algo_name = (char *)val;
 459         size_t name_len = strlen(algo_name);
 460
 461         if (algo_name[name_len - 1] == '\n')
 462                 algo_name[name_len - 1] = '\0';
 463
 464         bat_algo_ops = batadv_algo_get(algo_name);
 465         if (!bat_algo_ops) {
 466                 pr_err("Routing algorithm '%s' is not supported\n", algo_name);
 467                 return -EINVAL;
 468         }
 469
 470         return param_set_copystring(algo_name, kp);
 471 }
 472
 473 static const struct kernel_param_ops batadv_param_ops_ra = {
 474         .set = batadv_param_set_ra,
 475         .get = param_get_string,
 476 };
 477
 478 static struct kparam_string batadv_param_string_ra = {
 479         .maxlen = sizeof(batadv_routing_algo),
 480         .string = batadv_routing_algo,
 481 };
 482
 483 module_param_cb(routing_algo, &batadv_param_ops_ra, &batadv_param_string_ra,
 484                 0644);
 485 module_init(batadv_init);
 486 module_exit(batadv_exit);
 487
 488 MODULE_LICENSE("GPL");
 489
 490 MODULE_AUTHOR(BATADV_DRIVER_AUTHOR);
 491 MODULE_DESCRIPTION(BATADV_DRIVER_DESC);
 492 MODULE_SUPPORTED_DEVICE(BATADV_DRIVER_DEVICE);
 493 MODULE_VERSION(BATADV_SOURCE_VERSION);